Wave beam scanning array antenna based on substrate integrated cavity

Abstract

The invention provides a beam scanning array antenna based on a substrate integrated cavity. The beam scanning array antenna comprises an upper-layer substrate, a middle-layer substrate and a lower-layer substrate which are sequentially arranged from top to bottom, a slot array is arranged on the upper surface of the upper-layer substrate, an upper-layer substrate integrated cavity is arranged in the upper-layer substrate, and the upper-layer substrate integrated cavity is arranged around the slot array; a feed probe is arranged on the upper surface of the middle-layer substrate, a middle-layer substrate integrated cavity is arranged in the middle-layer substrate, the middle-layer substrate integrated cavity is arranged around the feed probe, and the upper-layer substrate integrated cavity is connected with the middle-layer substrate integrated cavity; the upper surface of the lower substrate is provided with a feed structure and a signal transmission structure. The cavity structures of the upper-layer substrate integrated cavity and the middle-layer substrate integrated cavity can effectively inhibit surface waves from being transmitted along the substrate, in addition, the cavity structures are formed around the feed probes, feed coupling can be effectively reduced, and therefore the performance of the antenna is improved.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a beam scanning array antenna based on a substrate integrated cavity. Background Art

[0002] With the rapid development of wireless communication technology, the millimeter wave frequency band has attracted people's attention and research due to its rich spectrum resources. Antennas, as important components in wireless communication systems, are also developing in the direction of miniaturization, multi-polarization, and high gain. As the frequency increases, antenna performance is easily affected by material properties and process limitations. Low Temperature Co-fired Ceramic (LTCC) technology has attracted widespread attention due to its flexible lamination process. However, due to the high dielectric constant of LTCC materials, the LTCC process is prone to excitation of surface waves. These waves propagate on the surface of the material, thereby increasing the coupling between units and deteriorating the antenna performance. Summary of the invention

[0003] In order to solve the technical problems existing in the prior art, the present invention provides a beam scanning array antenna based on a substrate integrated cavity. The cavity structure of the upper substrate integrated cavity and the middle substrate integrated cavity can effectively suppress the transmission of surface waves along the substrate. In addition, the cavity structure is formed around the feeding probe, which can effectively reduce the feeding coupling, thereby improving the performance of the antenna.

[0004] The present invention provides a beam scanning array antenna based on a substrate integrated cavity, comprising an upper substrate, a middle substrate and a lower substrate arranged in sequence from top to bottom; a slot array is arranged on the upper surface of the upper substrate, an upper substrate integrated cavity is arranged in the upper substrate, and the upper substrate integrated cavity is arranged around the slot array; a feeding probe is arranged on the upper surface of the middle substrate, a middle substrate integrated cavity is arranged in the middle substrate, and the middle substrate integrated cavity is arranged around the feeding probe, and the upper substrate integrated cavity is connected to the middle substrate integrated cavity, so as to suppress the surface The wave is transmitted along the substrate; a feeding structure and a signal transmission structure are provided on the upper surface of the lower substrate, the input end of the feeding structure is connected to the external chip, the output end of the feeding structure is connected to the input end of the signal transmission structure, and the output end of the signal transmission structure is connected to the input end of the feeding probe; the feeding structure is used to transmit the signal of the external chip to the feeding probe through the signal transmission structure; the feeding probe is used to transmit the received signal to the slot array; the slot array is used to convert and radiate the received signal to form an electromagnetic wave for beam scanning.

[0005] According to a beam scanning array antenna based on a substrate integrated cavity provided by the present invention, the slot array is a one-drive four-slot array, the one-drive four-slot array includes four slot units, each of which is rectangular in shape; the feeding mode of the one-drive four-slot array is TE 220 mold.

[0006] According to a beam scanning array antenna based on a substrate integrated cavity provided by the present invention, the upper substrate integrated cavity is a rectangular cavity surrounded by a plurality of first via holes, and the middle substrate integrated cavity is a rectangular cavity surrounded by a plurality of second via holes; the first via holes penetrate the corresponding second via holes.

[0007] According to a beam scanning array antenna based on a substrate integrated cavity provided by the present invention, the thickness of the middle substrate is greater than the thickness of the upper substrate, and the thickness of the upper substrate is greater than the thickness of the lower substrate.

[0008] According to a beam scanning array antenna based on a substrate integrated cavity provided by the present invention, the signal transmission structure is a columnar quasi-coaxial structure; the quasi-coaxial structure is embedded in the middle-layer substrate and located in the middle-layer substrate integrated cavity; the bottom of the quasi-coaxial structure serves as the input end of the signal transmission structure, and the top of the quasi-coaxial structure serves as the output end of the signal transmission structure.

[0009] According to a beam scanning array antenna based on a substrate integrated cavity provided by the present invention, the quasi-coaxial structure includes a plurality of third via holes, and the plurality of third via holes are evenly surrounded to form an inner coaxial structure.

[0010] According to a beam scanning array antenna based on a substrate integrated cavity provided by the present invention, the quasi-coaxial structure, the upper substrate integrated cavity and the middle substrate integrated cavity together serve as a periodic unit.

[0011] A beam scanning array antenna based on a substrate integrated cavity provided according to the present invention also includes a notch suppression via hole; the notch suppression via hole is embedded in the middle layer substrate and located in the middle layer substrate integrated cavity, and is used to suppress the notch.

[0012] According to a beam scanning array antenna based on a substrate integrated cavity provided by the present invention, the number of the notch suppression vias is 2, and the two notch suppression vias are symmetrically arranged on both sides of the quasi-coaxial structure.

[0013] According to a beam scanning array antenna based on a substrate integrated cavity provided by the present invention, for a frequency of 94 GHz and beam scanning at phi=90, the beam coverage range of the antenna is .

[0014] The present invention provides a beam scanning array antenna based on a substrate integrated cavity, comprising an upper substrate, a middle substrate and a lower substrate arranged in sequence from top to bottom; a slot array is arranged on the upper surface of the upper substrate, an upper substrate integrated cavity is arranged in the upper substrate, and the upper substrate integrated cavity is arranged around the slot array; a feeding probe is arranged on the upper surface of the middle substrate, a middle substrate integrated cavity is arranged in the middle substrate, and the middle substrate integrated cavity is arranged around the feeding probe, and the upper substrate integrated cavity is connected to the middle substrate integrated cavity; a feeding structure and a signal transmission structure are arranged on the upper surface of the lower substrate. The cavity structures of the upper substrate integrated cavity and the middle substrate integrated cavity of the present invention can effectively suppress the transmission of surface waves along the substrate. In addition, the cavity structure is formed around the feeding probe, which can effectively reduce the feeding coupling, thereby improving the performance of the antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a structural schematic diagram of a beam scanning array antenna based on a substrate integrated cavity provided by the present invention.

[0017] Figure 2 It is a comparison of the standing wave characteristic curves with and without a quasi-coaxial structure.

[0018] Figure 3 It is a comparison of the gain curves with and without quasi-coaxial.

[0019] Figure 4 is the array beam scanning curve.

[0020] Reference numerals: 1: upper substrate; 2: middle substrate; 3: lower substrate; 4: slot array; 5: upper substrate integrated cavity; 6: feeding probe; 7: middle substrate integrated cavity; 8: feeding structure; 9: signal transmission structure; 10: notch suppression via. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] With the continuous development of communication technology, spectrum resources in traditional microwave frequency bands are becoming increasingly scarce. In order to alleviate this problem, people have gradually turned their attention to the higher frequency millimeter wave band. Millimeter waves have attracted widespread attention due to their short wavelength, wide frequency band, and fast transmission rate. In wireless communication systems, both signal transmission and reception rely on antennas. As a key component in millimeter wave communication systems, millimeter wave antennas have a vital impact on the final performance of the system. In the millimeter wave band, as the frequency increases, antenna performance is easily affected by material properties and process limitations. Since millimeter waves have a large attenuation when propagating in the air, this requires millimeter wave antennas to have higher gain to be suitable for long-distance millimeter wave wireless communications. Low-temperature co-fired ceramic (LTCC) technology, due to its unique lamination process, makes antenna structure design more diversified, and can expand the layout of antenna from two-dimensional plane space to three-dimensional space, so that the antenna structure is more compact, providing the necessary conditions for the design of miniaturized millimeter-wave antennas; LTCC technology can realize the integrated three-dimensional integration of antenna and feed network, providing convenient conditions for the realization of high-gain millimeter-wave antennas; LTCC technology can also integrate antennas with other active and passive millimeter-wave devices in the same LTCC substrate, realizing the integration and modularization of the entire system; in addition, LTCC technology is a parallel processing technology, and each layer of the substrate can be processed in parallel, with high processing efficiency, and the LTCC process is convenient for automated large-scale mass production, reducing the cost of antenna products. However, in the millimeter-wave frequency band, the relatively large dielectric constant of LTCC will lead to greater surface wave loss, thereby reducing the gain of the antenna; and the propagation of surface waves along the antenna substrate will increase the mutual coupling between the array elements in the antenna, deteriorate the standing wave characteristics, narrow the antenna bandwidth, and deteriorate the cross-polarization characteristics, limiting the improvement of antenna gain.

[0023] Please refer to Figure 1 , Figure 1 A schematic structural diagram of a beam scanning array antenna based on a substrate integrated cavity provided by the present invention.

[0024] The present invention provides a beam scanning array antenna based on a substrate integrated cavity, comprising an upper substrate 1, a middle substrate 2 and a lower substrate 3 which are arranged in sequence from top to bottom; a slot array 4 is arranged on the upper surface of the upper substrate 1, an upper substrate integrated cavity 5 is arranged in the upper substrate 1, and the upper substrate integrated cavity 5 is arranged around the slot array 4; a feeding probe 6 is arranged on the upper surface of the middle substrate 2, a middle substrate integrated cavity 7 is arranged in the middle substrate 2, and the middle substrate integrated cavity 7 is arranged around the feeding probe 6, and the upper substrate integrated cavity 5 is connected to the middle substrate integrated cavity 7, for Suppress the transmission of surface waves along the substrate; a feeding structure 8 and a signal transmission structure 9 are provided on the upper surface of the lower substrate 3, the input end of the feeding structure 8 is connected to the external chip, the output end of the feeding structure 8 is connected to the input end of the signal transmission structure 9, and the output end of the signal transmission structure 9 is connected to the input end of the feeding probe 6; the feeding structure 8 is used to transmit the signal of the external chip to the feeding probe 6 through the signal transmission structure 9; the feeding probe 6 is used to transmit the received signal to the slot array 4; the slot array 4 is used to convert and radiate the received signal to form an electromagnetic wave for beam scanning.

[0025] In order to solve the technical problems existing in the prior art, the present invention provides a beam scanning array antenna based on a substrate integrated cavity, comprising an upper substrate 1, a middle substrate 2 and a lower substrate 3.

[0026] The upper surface of the upper substrate 1 is provided with a slot array 4, and the upper substrate integrated cavity 5 is designed to be rectangular and arranged around the slot array 4. Due to its inherent cavity structure, it can effectively suppress the transmission of surface waves along the substrate, thereby improving the performance of the antenna. The resonant frequency of the upper substrate integrated cavity 5 can be calculated by the formula Calculate, where c is the speed of light, is the relative dielectric constant of the medium.

[0027] A feeding probe 6 is provided on the upper surface of the middle substrate 2, and the feeding probe 6 has a low surface roughness to minimize the loss during signal transmission. The middle substrate integrated cavity 7 is arranged around the feeding probe 6, and its structure and function are similar to the upper substrate integrated cavity 5. Since the cavity structure is formed around the feeding probe 6, it can effectively reduce the coupling of the feeding between the units and improve the quality factor of the feeding network.

[0028] The upper surface of the lower substrate 3 is provided with a feeding structure 8 and a signal transmission structure 9. The feeding structure 8 is connected to the output end of an external chip (such as a signal generator or a radio frequency power amplifier). The signal transmission structure 9 can adopt a quasi-coaxial design.

[0029] In order to achieve beam scanning, the input end of the feeding probe 6 is connected to the output end of the signal transmission structure 9. By controlling the phase and amplitude of the signal generated by the external chip, the direction of the electromagnetic wave radiated by the slot array 4 can be controlled. For example, by changing the signal phase at the feeding probe 6, the beam can be deflected in the horizontal plane.

[0030] As a preferred embodiment, the slot array 4 is a one-drive four-slot array, which includes four slot units, each of which is rectangular in shape; the feeding mode of the one-drive four-slot array is TE 220 mold.

[0031] In order to improve the gain of the antenna array and reduce the overall feeding loss, in this embodiment, the slot array 4 can adopt an aperture coupling method to realize a one-drive four-slot array as a unit structure, and based on the TE of the cavity 220 The TE mode feeds four slot units, replacing the traditional power divider and reducing the feeder loss caused by power combination. Each slot unit is rectangular in shape. 220 A type of cavity resonant mode, where TE stands for transverse electric mode and 220 means that the mode has two nodes in two dimensions. This mode has a specific field distribution, and the distribution of the electric field at the gap is particularly suitable for exciting gap radiation. By adjusting the size and material of the cavity, the resonant frequency can be precisely controlled.

[0032] In order to achieve TE 220 For modal feeding, the feeding probe 6 is designed to be aligned with the center of the slot array 4 to ensure uniform energy distribution to each slot unit. The feeding probe 6 is connected to the middle substrate integrated cavity 7 through a precisely designed coupling hole, the position and size of which are optimized to achieve efficient mode conversion and minimal loss. In the beam scanning operation, by adjusting the phase of the feeding probe 6, the phase difference of the electromagnetic wave radiated by the slot array 4 can be controlled, thereby achieving directional scanning of the beam. By precisely controlling the feeding phase of each slot unit, accurate scanning of the beam in the desired direction can be achieved.

[0033] As a preferred embodiment, the upper substrate integrated cavity 5 is a rectangular cavity surrounded by a plurality of first via holes, and the middle substrate integrated cavity 7 is a rectangular cavity surrounded by a plurality of second via holes; the first via holes penetrate the corresponding second via holes.

[0034] In this embodiment, the substrate integrated cavity of the antenna is designed to be rectangular to optimize the resonance characteristics and radiation mode of the cavity. The cavity structure can effectively suppress the transmission of surface waves, thereby reducing the mutual coupling between units. The upper substrate integrated cavity 5 and the middle substrate integrated cavity 7 are both surrounded by multiple vias, which play a vital role in the construction of the cavity.

[0035] The upper substrate integrated cavity 5 is located in the upper substrate 1 and is directly arranged around the slot array 4. The cavity is surrounded by 52 first vias, and each via can ensure the integrity and rigidity of the cavity.

[0036] The middle substrate integrated cavity 7 is located in the middle substrate 2 and arranged around the feeding probe 6. The cavity is surrounded by 52 second vias. The layout of the second vias is intended to maximize the resonant frequency of the cavity and minimize interference with the feeding probe 6.

[0037] The design of the first and second vias not only considers the structural integrity of the cavity, but also the transmission efficiency of electromagnetic waves. The conductivity of the vias is very high, so they introduce little loss in the transmission of RF signals. In addition, the vias also help provide good electromagnetic shielding, thereby reducing mutual interference between different antenna units.

[0038] In order to achieve efficient signal transmission, the upper substrate integrated cavity 5 and the middle substrate integrated cavity 7 are connected through corresponding vias. This connection method allows the signal to be smoothly transmitted from the feeding structure 8 of the lower substrate 3 to the feeding probe 6 of the middle substrate 2, and finally to the slot array 4 of the upper substrate 1. By controlling the resonant frequency of the upper substrate integrated cavity 5 and the middle substrate integrated cavity 7, precise control of the beam scanning direction can be achieved.

[0039] In addition, by adjusting the number and layout of vias, the resonance characteristics and radiation pattern of the cavity can be further optimized. For example, increasing the number of vias can increase the resonance frequency of the cavity, while reducing the number of vias can reduce the resonance frequency.

[0040] As a preferred embodiment, the thickness of the middle substrate 2 is greater than the thickness of the upper substrate 1 , and the thickness of the upper substrate 1 is greater than the thickness of the lower substrate 3 .

[0041] In this embodiment, the performance of the antenna is optimized by designing a substrate thickness gradient, which helps in beam forming and control, and also improves the structural stability and mechanical strength of the antenna.

[0042] The lower substrate 3 carries the feeding structure 8 and the signal transmission structure 9, and is designed to be the thinnest in order to reduce the overall weight of the antenna while providing sufficient rigidity to support the upper structure. The upper substrate 1 is thicker than the lower substrate 3 to accommodate the setting of the slot array 4 and the integration of the upper substrate integrated cavity 5. The middle substrate 2 is the thickest of the three substrates. The middle substrate 2 not only carries the feeding probe 6 and the middle substrate integrated cavity 7, but its thickness also helps to provide additional isolation and reduce crosstalk and electromagnetic interference between different layers.

[0043] The increase in thickness also means that the path of the signal when propagating inside the substrate becomes longer, which helps to adjust the phase of the signal and thus achieve beam scanning.

[0044] As a preferred embodiment, the signal transmission structure 9 is a columnar quasi-coaxial structure; the quasi-coaxial structure is embedded in the middle-layer substrate 2 and is located in the middle-layer substrate integrated cavity 7; the bottom of the quasi-coaxial structure serves as the input end of the signal transmission structure 9, and the top of the quasi-coaxial structure serves as the output end of the signal transmission structure 9.

[0045] In this embodiment, the signal transmission structure 9 adopts a columnar quasi-coaxial structure, and the height of the quasi-coaxial structure matches the thickness of the middle substrate 2. The quasi-coaxial structure is embedded in the middle substrate 2 and is precisely located in the middle substrate integrated cavity 7. This design helps to protect the signal transmission path and reduce the impact of external electromagnetic interference on signal integrity. The bottom of the quasi-coaxial structure is connected to the feeding structure 8 of the lower substrate 3 as the input end of the signal transmission structure 9. The top is connected to the feeding probe 6 of the middle substrate 2 as the output end of the signal transmission structure 9.

[0046] The signal is transmitted from the external chip to the feeding structure 8 of the lower substrate 3, and then transmitted to the feeding probe 6 of the middle substrate 2 through the quasi-coaxial structure, and the energy is transmitted to the four slot antenna units on the top through the aperture coupling feeding method. This transmission method takes advantage of the low-loss characteristics of the coaxial structure to ensure that the signal loss during transmission is minimized. The design of the quasi-coaxial structure also helps to suppress mode conversion and the generation of high-order modes during signal transmission, thereby maintaining signal quality and phase consistency.

[0047] As a preferred embodiment, the quasi-coaxial structure includes a plurality of third via holes, and the plurality of third via holes are evenly surrounded to form an inner coaxial structure.

[0048] In this embodiment, eight third vias are uniformly integrated in the quasi-coaxial structure, and the height of these vias is the same as that of the middle substrate 2. These third vias form an inner coaxial structure, which helps to provide a more uniform electromagnetic field distribution, thereby reducing the loss of the signal during transmission and improving the impedance matching.

[0049] As a preferred embodiment, the quasi-coaxial structure, the upper substrate integrated cavity 5 and the middle substrate integrated cavity 7 together serve as a periodic unit.

[0050] In order to realize the beam scanning of the SIC (Substrate Integrated Cavity) antenna array, the chip needs to be connected to the SIC unit through a quasi-coaxial structure. Since the quasi-coaxial structure has a circle of third vias around it, in this embodiment, the quasi-coaxial structure and the upper substrate integrated cavity 5 and the middle substrate integrated cavity 7 are used as a periodic unit overall structure to eliminate the influence of the circle of third vias of the quasi-coaxial structure on the SIC unit.

[0051] As a preferred embodiment, it also includes a notch suppression via 10; the notch suppression via 10 is embedded in the middle substrate 2 and located in the middle substrate integrated cavity 7, and is used to suppress the notch.

[0052] Since the quasi-coaxial structure in the middle substrate integrated cavity 7 may cause self-resonance and lead to the deterioration of the gain curve, in this embodiment, the notch suppression via 10 is not only embedded in the middle substrate 2, but also accurately positioned in the middle substrate integrated cavity 7. This design helps to suppress the notch that may be caused by the material, structure or operating frequency without affecting the resonance characteristics of the cavity. The number of vias is determined according to the size of the cavity and the required notch suppression effect, and is assumed to be 4, evenly distributed in the cavity.

[0053] As a preferred embodiment, the number of the notch suppression via holes 10 is two, and the two notch suppression via holes 10 are symmetrically arranged on both sides of the quasi-coaxial structure.

[0054] In this embodiment, the notch suppression vias 10 can be symmetrically arranged on both sides of the quasi-coaxial structure to eliminate the self-resonance that may be caused by the quasi-coaxial structure in the cavity, thereby eliminating the notch in the band, thereby improving the antenna gain flatness and improving the antenna performance.

[0055] Notch waves are usually caused by electromagnetic waves encountering structural discontinuities or changes in dielectric properties during propagation. The notch suppression via 10 provides a continuous path to reduce discontinuous reflections of the signal in the cavity, thereby suppressing notch waves. The introduction of vias helps to even out the electromagnetic field distribution and reduce the standing wave ratio inside the cavity.

[0056] Please refer to Figure 2 , Figure 2 To compare the standing wave characteristic curves with and without the quasi-coaxial structure.

[0057] Please refer to Figure 3 , Figure 3 To compare the gain curves with and without quasi-coaxial.

[0058] Figure 2 The standing wave curves of three types of SIC units, namely, the traditional non-classical coaxial structure, the classical coaxial structure only, and the classical coaxial and notch suppression vias, are compared. Figure 3 The corresponding gain curves of the three cases are compared. Figure 2 and 3 It can be seen that a quasi-coaxial structure necessary for connecting the chip is added to the traditional SIC unit, and it can be found that there are obvious notches at 95.6 and 97 GHz in the gain passband. For this reason, the present invention proposes to effectively eliminate the notches in the passband by adding and adjusting the positions of vias on both sides of the quasi-coaxial.

[0059] As a preferred embodiment, for the frequency 94 GHz and phi=90 beam scanning, the antenna beam coverage is .

[0060] Please refer to Figure 4 , Figure 4 is the array beam scanning curve.

[0061] In this embodiment, the chip is connected to the SIC unit through a quasi-coaxial connection, and beam scanning can be achieved by controlling the output phase of the chip. In order to increase the overall gain of the antenna, the beam scanning range is sacrificed. Figure 4 The beam scanning situation at phi=90 at 94GHz is given, and the beam coverage range can reach The case of Pi=0 is similar and will not be described in detail.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A beam scanning array antenna based on a substrate integrated cavity, characterized in that: It includes an upper substrate, a middle substrate and a lower substrate which are arranged in sequence from top to bottom; A slot array is arranged on the upper surface of the upper substrate, an upper substrate integrated cavity is arranged in the upper substrate, and the upper substrate integrated cavity is arranged around the slot array; a feeding probe is arranged on the upper surface of the middle substrate, a middle substrate integrated cavity is arranged in the middle substrate, and the middle substrate integrated cavity is arranged around the feeding probe, and the upper substrate integrated cavity is connected to the middle substrate integrated cavity to suppress the transmission of surface waves along the substrate; a feeding structure and a signal transmission structure are arranged on the upper surface of the lower substrate, the input end of the feeding structure is connected to an external chip, the output end of the feeding structure is connected to the input end of the signal transmission structure, and the output end of the signal transmission structure is connected to the input end of the feeding probe; The feeding structure is used to transmit the signal of the external chip to the feeding probe through the signal transmission structure; The feeding probe is used to transmit the received signal to the slot array; the slot array is used to convert and radiate the received signal to form an electromagnetic wave for beam scanning.

2. The beam scanning array antenna based on substrate integrated cavity according to claim 1, characterized in that: The slot array is a one-drive four-slot array, the one-drive four-slot array includes four slot units, each of which is rectangular in shape; the feeding mode of the one-drive four-slot array is TE 220 mold.

3. The beam scanning array antenna based on substrate integrated cavity according to claim 1, characterized in that: The upper substrate integrated cavity is a rectangular cavity surrounded by a plurality of first via holes, and the middle substrate integrated cavity is a rectangular cavity surrounded by a plurality of second via holes; the first via holes penetrate the corresponding second via holes.

4. The beam scanning array antenna based on substrate integrated cavity according to claim 1, characterized in that: The thickness of the middle substrate is greater than that of the upper substrate, and the thickness of the upper substrate is greater than that of the lower substrate.

5. The beam scanning array antenna based on substrate integrated cavity according to claim 1, characterized in that: The signal transmission structure is a columnar quasi-coaxial structure; the quasi-coaxial structure is embedded in the middle-layer substrate and located in the middle-layer substrate integrated cavity; the bottom of the quasi-coaxial structure serves as the input end of the signal transmission structure, and the top of the quasi-coaxial structure serves as the output end of the signal transmission structure.

6. The beam scanning array antenna based on substrate integrated cavity according to claim 5, characterized in that: The quasi-coaxial structure includes a plurality of third via holes, and the plurality of third via holes are evenly surrounded to form an inner coaxial structure.

7. The beam scanning array antenna based on substrate integrated cavity according to claim 5, characterized in that: The quasi-coaxial structure, the upper substrate integrated cavity and the middle substrate integrated cavity together serve as a periodic unit.

8. The beam scanning array antenna based on substrate integrated cavity according to claim 5, characterized in that: It also includes a notch suppression via hole; the notch suppression via hole is embedded in the middle layer substrate and located in the middle layer substrate integrated cavity, and is used to suppress the notch.

9. The beam scanning array antenna based on substrate integrated cavity according to claim 8, characterized in that: The number of the notch suppression via holes is 2, and the two notch suppression via holes are symmetrically arranged on both sides of the quasi-coaxial structure.

10. The beam scanning array antenna based on substrate integrated cavity according to any one of claims 1 to 9, characterized in that: For the frequency 94 GHz at phi = 90 beam scanning, the beam coverage of the antenna is .

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